PROJECT SUMMARY/ABSTRACT The long-term research goal is to reduce obesity and obesity-related health problems among minority youth by examining the critical role of sleep in the etiology of obesity in these populations. Targeted health promotion strategies to address the complex and interacting multilevel factors that lead to adiposity are needed. The innovative objectives of the proposed project are: 1) to identify individual, social, and environmental-level antecedents of sleep duration, quality, and timing in Latino youth; and 2) to enhance best practices for improving sleep tailored to this vulnerable group. The Specific Aims are: Aim 1: To use qualitative methods to elucidate the individual (psychological and behavioral), social (interpersonal), and environmental (community) level factors that influence sleep duration, quality and timing among Latino pre-adolescents. Aim 2: To examine whether real-time daily variations in psychological, behavioral and interpersonal factors (assessed via EMA) influence sleep duration, quality, and timing (assessed via actigraphy) among 140 Latino pre-adolescents. Strategies resulting from the proposed research present novel, modifiable intervention modalities to improve and restore energy balance in Latino children, a population disproportionately impacted by obesity and related health disparities. This type of intervention will lend to achieving the third goal of the National Center on Sleep Disorders Research to prevent chronic sleep deficiency, which will significantly influence numerous health outcomes. In-depth exploration of relevant contextual issues with qualitative methods (focus groups) and quantitative micro-longitudinal methods (ecological momentary assessment [EMA]) will be used to collect momentary data on the multi-level factors of importance for enhancing sleep health. The overarching goal of this application is for the candidate to develop into an independent transdisciplinary obesity prevention researcher by obtaining training in pediatric sleep actigraphy, EMA, mixed methods analyses, and community-based intervention. Results from the proposed observational study will provide preliminary data to be used for publications and to support development of proposals to procure R01- level funding. Career development will take place in a diverse, student-centered, globally engaged, public university committed to providing highly valued educational opportunities through superior teaching, research, and service for the people of California and the world.